The present invention relates to a sliding track assembly for drawer and, more specifically, to an auto-locking structure used in a sliding track assembly for drawer.
FIG. 1 illustrates an auto-locking structure used in a sliding track assembly for drawer according to the prior art. According to this design, the auto-locking structure comprises a seat 911, a spring member 912 and a link 913 respectively installed in the outer sliding rail 91, and an engagement block 921 installed in the inner sliding rail 92. This design of auto-locking structure is not satisfactory in function. Because the seat 911 occupies much rear side space of the outer sliding rail 91, it weakens the functioning of the outer sliding rail 91 to bear the load.
It is the main object of the present invention to provide an auto-locking structure for use in a sliding track assembly for drawer, which requires less installation space in the sliding track assembly. It is another object of the present invention to provide an auto-locking structure for use in a sliding track assembly, which does not weaken the functioning of the sliding track assembly to bearing the load. According to one aspect of the present invention, the auto-locking structure comprises a track fastened to the outer sliding rail of the sliding track assembly, a sliding locking block movably supported in the track, a spring member connected between the track and the sliding locking block, and a push block located on the inner sliding rail of the sliding track assembly. The track provides a sliding groove formed of a linear front sliding groove portion and a arched rear sliding groove portion and a hook hole biased from the front side of the linear front sliding groove portion to match the sliding locking block. The sliding locking block has a locating rod, a sloping wall, and a side locating hole. The push block has a push rod adapted to mach the sliding locking block to achieve an auto-locking action. Because the track and the sliding locking block have a limited size, they occupy small installation space in the outer sliding rail without affecting the functioning of the sliding track assembly to carry the load. According to another aspect of the present invention, when the inner sliding rail pushed backwards to force the back sidewall of the sliding locking block against the front sidewall of the first locating block of the track, the rear end of one lateral sidewall of the inner sliding rail is automatically forced into engagement with a clamping portion of the first locating block of the track, and therefore the inner sliding rail is positively held in position. According to still another aspect of the present invention, the sliding locking block has an opening adjacent to the sloping wall and the side locating hole, such that the sloping wall of the sliding locking block can be deformed by the push rod of the push block for enabling the push rod to move into the side locating hole to achieve an locking action when the sliding locking block forced by an unexpected external force and pulled backwards by the spring member.